1. Field of the Invention
The present invention relates to a radiotherapy device control apparatus and a radiation irradiation method, and more specifically to a radiotherapy device control apparatus and a radiation irradiation method for use in treating a patient by irradiating his or her affected area with radiation.
2. Description of the Related Art
Radiotherapy is known which treats a patient by irradiating his or her affected area (tumor) with radiation. It is desired that the radiotherapy provides a high therapeutic effect and that a dosage of radiation thereof irradiated to normal cells be smaller than a dosage of radiation irradiated to cells at the affected area.
The radiotherapy device is known which tracks a position of an affected area based on transmitted images photographed by applying diagnostic X-rays, and irradiates the position with a radiation for treatment. It is desired that a dosage of the diagnostic X-rays to a patient be as small as possible.
Japanese patent JP3746747B discloses a radiotherapy device capable of monitoring, in real time, condition of a treatment field even during radiation irradiation treatment. The radiotherapy device includes: a radiation irradiation head which irradiates a treatment field of a subject with therapeutic radiation; an X-ray source which irradiates the treatment field of the subject with diagnostic X-rays; a sensor array which detects transmitted X-rays of the diagnostic X-rays transmitted through the subject and then outputs them as diagnostic image data. The sensor array moves in conjunction with movement of the radiation irradiation head.
Japanese Laid Open Patent Application JP2004-121406A discloses a radiotherapy device capable of easily positioning, within a radiation irradiation range, a target to be irradiated with radiation. This radiotherapy device is characterized by being provided with: a radiation generator which emits radiation and laser beams concentrically with each other; a guide which moves the radiation generator along an orbit of a predetermined radius with respect to an isocenter serving as a center so that irradiation axes of the radiation and the laser beams emitted concentrically with each other intersect with each other at one point; a support member which rotates the guide around an inclined axis passing through the isocenter; a movable member which pivots the radiation generator by rotating axes intersecting with each other and moves along the guide; a detector which detects information of a transmitted image in a range including the isocenter and the target to be irradiated with the radiation arranged near the isocenter; an analyzer which calculates relative positional relationship between the isocenter and the target to be irradiated based on information of a plurality of the transmitted images respectively detected in a plurality of orientations by the detector and based on information of the orientations in which the transmitted images are detected with respect to the isocenter; and a controller which moves the radiation generator based on the relative positional relationship.
Japanese patent JP3053389B (corresponding to US6307914B) discloses a moving body tracing irradiation device capable of automatically calculating, in actual time, position of tumor moving around in the trunk and capable ensuring the actually required accuracy without depending on the absolute accuracy of a mechanical system. This moving body tracing irradiation device is characterized by being provided with: a linac which irradiates tumor with therapeutic beams; a tumor marker which is embedded near the tumor; a first x-ray fluoroscope which images the tumor marker from a first direction; a second x-ray fluoroscope which images the tumor marker from a second direction simultaneously with the first x-ray fluoroscope; a first and a second image input parts which digitize a first and a second fluoroscopic images outputted from the first and second x-ray fluoroscopes; a first and a second recognition processing parts which execute, at an actual time level of a predetermined frame rate, template matching by a gray scale normalization cross-correlation method in which a template image of a tumor marker previously registered is effected on image information digitized by the first and second image input parts to thereby obtain first and second two-dimensional coordinates of the tumor marker; a central processing part which calculates three-dimensional coordinates of the tumor marker from the first and second two-dimensional coordinates calculated by the first and second recognition processing parts; and an irradiation control part which controls the therapeutic beams of the linac based on the obtained three-dimensional coordinates of the tumor marker.
Japanese Patent JP3432268B discloses a radiotherapy system capable of resolving deterioration in accuracy in irradiation planning due to body movement of a subject during radiotherapy. The radiotherapy system is characterized by being provided with: in radiotherapy system performing radiotherapy by irradiating a subject with radiation, phase identification means adapted to establish association between the phase of living body data in accordance with the body movement of the subject detected in parallel with acquisition of a CT image of the subject and the phase of the CT image; plan data creation means adapted to, based on the CT image associated with the phase of the living body data by the phase identification means, create treatment plan data including opening and closing data of a collimator for adjusting a field to be irradiated with the radiation; determination means adapted to determine correlation between the living body data associated with the phase of the CT image and the living body data in accordance with the body movement of the subject obtained during the radiotherapy; and collimator control means adapted to, in accordance with a result of determination made by the determination means, perform opening and closing control of the collimator based on the opening and closing data.
Japanese Patent JP3326597B discloses a respiration synchronizing control device. This control device is characterized by the use of function of a semiconductor position detecting element (PSD) and composed of: a light source part with a light source position or a light direction fluctuating in correspondence with the fluctuation of the outer skin of an organism interlocked with respiration; the PSD receiving light from the light source part, as a fluctuation signal of the outer skin of the organism and converting it into an electric signal corresponding to the cycle phase of respiration; and a control circuit sending an actuation control signal of other controlled equipment on the basis of this electric signal.
Japanese Laid Open Patent Application JP H4-507048A (corresponding to WO9011721) discloses a patient alignment system and procedure for radiation treatment. In this patent, accurate and repeatable patient alignment with a charged-particle beam of a radiation beam therapy system, such as a proton beam delivery system, is provided. The patient is immobilized within a formfit patient pod. Reference radiographs are prepared with an X-ray system that is used for repositioning the patient within the pod on subsequent occasions. CT scan data is obtained using a CT Scan System of a particular tissue volume of interest, such as a region of the patient wherein a cancerous tumor is located, while the patient remains in the pod. The CT scan data is used to prepare a treatment plan for the patient. The treatment plan includes identifying an isocenter within the tissue volume at which the beam is to be directed from a selected angle(s). A computer simulation of the treatment plan is performed to optimize the treatment plan.
Japanese Patent JP3394250B (corresponding to WO92006644) discloses an apparatus for and method of stereotaxic surgery. The method and the apparatus are set forth for selectively irradiating a target within a patient. A 3-dimensional mapping is provided of a mapping region surrounding the target. A beaming apparatus emits a collimated beam. Diagnostic beams at a known non-zero angle to one another pass through the mapping region. They produce images of projections within the mapping region. Electronic representations of the images are compared with the reference data thereby locating the target. The relative positions of the beaming apparatus and the living organism are adjusted in such a manner that the collimated beam is focused on the target region. The comparison is repeated at small time intervals and, when the comparison so indicates, the adjusting step is repeated, as needed, and in such a manner that the collimated beam remains focused onto the target region.
Japanese Laid Open Patent Application JP H8-511452A (corresponding to WO9428971) discloses a radiotherapy system. The radiation therapy machine having constrained angular freedom to produce a beam only within a gantry plane. A radiation shield may be stationary and not attached to the gantry or rotating to always block the primary beam. The constrained motion reduces the risk of patient/gantry collision and provides for extremely accurate radiation therapy planning. The therapy machine, so constrained, may include a tomographic imaging system on a single gantry. The two systems cooperate and employ many of the same hardware components to both plan and carry out therapy sessions in which irregularly shaped treatment volumes are accurately irradiated while tissue surrounding those volumes is minimally irradiated. The therapy machine also may include a collimator that changes the width of a fan beam of radiation as a treatment volume of the patient crosses the volume exposed by the beam so as to minimize the irradiation of healthy tissue at the front and back of the tumor. The width of the fan beam may be controlled to treat multiple adjacent, similar slices of the patient at one time reducing the treatment duration.